Method and apparatus for scaling handwritten character input for handwriting recognition

Abstract

A method, computer program product, and a data processing system for scaling handwritten character input for performing handwriting recognition. A stroke parameter is derived from a handwritten character stroke and an input area is calculated in which the handwritten character stroke was supplied. The stroke parameter is scaled according to the input area.

1. A method for scaling handwritten character input for performing handwriting recognition, the method comprising the computer implemented steps of:
 deriving a first stroke parameter from a first handwritten character stroke; 
 calculating an input area in which the first handwritten character stroke was supplied; and 
 scaling the first stroke parameter according to the input area, wherein scaling comprises multiplying the first stroke parameter with a ratio of a reference area to the input area. 
 
   
   
     2. The method of  claim 1 , wherein the step of deriving includes:
 detecting a first start point and first end point of the first handwritten character stroke. 
 
   
   
     3. The method of  claim 1 , wherein the first input area bounds the first handwritten character stroke at a first coordinate extrema of the first handwritten character stroke. 
   
   
     4. The method of  claim 1 , wherein the step of deriving includes:
 calculating a first length parameter of the first handwritten character stroke. 
 
   
   
     5. The method of  claim 4 , wherein the step of calculating includes:
 squaring the first length parameter of the first handwritten character stroke. 
 
   
   
     6. The method of  claim 1 , further including:
 determining first coordinates of a first start point and first end point of the first handwritten character stroke; 
 determining second coordinates of a second start point and a second end point of a second handwritten character stroke, wherein the step of calculating includes identifying first coordinate extrema of the first coordinates of the first handwritten character stroke and second coordinate extrema of the second coordinates second handwritten character stroke. 
 
   
   
     7. A computer program product in a recordable-type medium for scaling a parameter derived from a handwritten character stroke, the computer program product comprising:
 first instructions for determining a first start point and a first end point of a first stroke input into a computer interface, responsive to determination of the first start point and the first end point, calculating a first stroke length parameter of the first stroke; and 
 second instructions for calculating an input area in which the first stroke was supplied and, responsive to calculating the input area, scaling the first stroke length parameter of the first stroke according to the input area, wherein scaling comprises multiplying the first stroke length parameter with a ratio of a reference area to the input area. 
 
   
   
     8. The computer program product of  claim 7 , wherein the input area bounds the first stroke at first coordinate extrema of the first stroke. 
   
   
     9. The computer program product of  claim 7 , wherein the second instructions scale the first stroke length parameter of the first stroke as a ratio of a reference area to the input area. 
   
   
     10. The computer program product of  claim 7 , wherein the first instructions further determine a second start point and a second end point of a second stroke input into the computer interface, and responsive to determination of the second start point and the second end point; and wherein the second instructions, responsive to the first instructions determining a second start point and a second end point of a second stroke input into the computer interface, recalculate the input area to determine a recalculated input area. 
   
   
     11. The computer program product of  claim 10 , wherein the first instructions calculate a second stroke length parameter of the second stroke. 
   
   
     12. The computer program product of  claim 11 , wherein the second instructions rescale the second stroke length parameter of the second stroke according to the recalculated input area. 
   
   
     13. The computer program product of  claim 10 , wherein the recalculated input area bounds the first stroke and the second stroke at first coordinate extrema of the first stroke and second coordinate extrema of the second stroke. 
   
   
     14. The computer program product of  claim 13 , wherein the second instructions rescale the first stroke length parameter of the first stroke according to the recalculated input area. 
   
   
     15. A data processing system comprising:
 a pointing device for receiving a first handwritten character stroke; 
 a memory that contains a set of instructions; and 
 a processing unit, responsive to an execution of the set of instructions, for determining a first start point and first end point of the first handwritten character stroke and calculating a first stroke length parameter from the first start point and the first end point and, responsive to determining the first start point and the first end point, for calculating an input area into which the first handwritten character stroke was supplied, wherein the first stroke length parameter is scaled according to the input area, wherein scaling comprises multiplying the first stroke length parameter with a ratio of a reference area to the input area. 
 
   
   
     16. The data processing system of  claim 15 , wherein the input area bounds the first handwritten character stroke at first coordinate extrema of the first handwritten character stroke. 
   
   
     17. The data processing system of  claim 15 , wherein the processing unit, responsive to determining a second start point and second end point of a second handwritten character stroke, recalculates the input area to determine a recalculated input area, wherein the recalculated input area bounds the first handwritten stroke and the second handwritten stroke at first coordinate extrema of the first handwritten character stroke and at second coordinate extrema of the second handwritten character stroke. 
   
   
     18. The data processing system of  claim 17 , wherein the processing unit, responsive to recalculating the input area, rescales the first stroke length parameter. 
   
   
     19. The data processing system of  claim 17 , wherein the processing unit, responsive to determining the second start point and the second end point of the second handwritten character stroke, calculates a second stroke length parameter of the second handwritten character stroke and scales the second stroke length parameter of the second handwritten character stroke in relation to the recalculated input area. 
   
   
     20. A computer program product in a recordable-type medium for scaling a parameter derived from a handwritten character stroke, the computer program product comprising:
 first instructions for displaying a collection area in a computer interface adapted to display a first stroke input into the collection area; 
 second instructions for calculating an input area in which the first stroke was supplied and, responsive to calculating the input area, scaling the stroke according to the input area, wherein scaling comprises multiplying the first stroke with a ratio of a reference area to the input area; and 
 third instructions for displaying the scaled stroke in a window of the computer interface. 
 
   
   
     21. The computer program product of  claim 20 , wherein the window is a predefined area of the computer interface. 
   
   
     22. The computer program product of  claim 20 , wherein the first instructions display a second stroke input in the collection area, the second instructions, responsive to input of the second stroke, recalculate the input area to determine a recalculated input area, scale the second stroke according to the recalculated input area to form a scaled second stroke, and rescale the first stroke according to the recalculated input area to form a rescaled first stroke. 
   
   
     23. The computer program product of  claim 22 , wherein the third instructions display the rescaled first stroke and the scaled second stroke in the window.